Escapement mechanism for typewriters



Jan. 12, 1932.

Filed Oct. 28 s Shee'ts-Sheet Jan. 12, 1932. LL 1,841,108

ESCAPEMENT MECHANISM FOR TYPEWRITERS FiledOct. 28 1927 3 Sheets-Sheet 2 Jan. 12, 1932. M. GARBELL I ESCAPEMENT MECHANISM FOR TYPEWRITERS Filed Oct. 28 1927 3 Sheets-Sheet 3 .Patentecl Jan. 12, 1932 UNITED STATES PATENT OFFICE MAX GARBELL, OF CHICAGO, ILLINOIS, AS SIGNOR TO VICTOR ADDING MACHINE COMPANY,.OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS ESCAPEMENT MECHANISM FOR TYIEWBITEBS Application filed October 28, 1927. Serial No. 229,439.

My invention relates to typewriters and it has particular relation to an advantageous combination of elements providing an efl'icicnt escapement mechanism and back- 5 spacing device for said machines.

The advantages of my improved construction for the above movements will be explained more at len th in connection with the hereinafter description of a machine l embodying my inventions, based on the accompanying drawings, in which:

Figure 1 is an elevational view partially in section and on a line fore and aft of a typewriter embodying my invention;

- Fig. 2 is a plan view of a number of the elements comprising my invention;

Figs. 2a and 2b are fragmentary perspective views of the escapem'ent brac e in plan in Fig. 2;

" Fig. 3 is a fragmentary elevational rear view of a portion of the escapement mechanism;

Fig. 4 is a rear elevational view of so much of the mechanism of the back spacing elements of my invention as are necessary to disclose an operative reduction reduction to practice of the same;

Fig. 4a is a detailed view showing a portion of the back-spacing mechanism;

13 Fig. 5 is an elevational sectional view taken on the line 55 of Fig. 4;

Fig. 6 is an elevational View taken on the line 66 of Fig. 5; and.

Fig. 7 is an elevational view, taken on the 5 line 7-7 of Fig. 5.

Referring now more particularly to the drawings, I will first describe as much of the type bar action of my machine as is necessary for a thorough understanding of the operation thereof. 7

I have shown a rear end of the key lever,

the same being pivoted at '11 in a c annelshaped collar 12, which latter is secured to a frame portion 13 of said collar, it being understood of course that the forward end of said lever is provided with a letter or number key, and that it is to be moved downwardlyor depressed to operate the type bars.

Intermediate levers such as 14 are pivoted 3 on a wire or equivalent member-15 in a segt shown I portlon 18 of the intermediate lever so that ment 16. The rear end of said intermediate levers 14 are shaped into universal operating feet 17 rising from which latter portion are toothed portions 18. Said intermediate levers 14 are slotted at 19 to receive a pin 20 mounted on an extension 21 of the key lever 10 so that a depression of the key lever 10 moves the intermediate levers 14 downwardly as shown in the dotted line in Fig. 1.

A plurality of type bars some of which are shown at 22, are mounted on a wire or equivalent member 23 in a segment 24. 'The particular segment which I have found to be most advantageous is more fully illustrated and claimed in my copending application Serial N 0. 286,948, filed December 1,1927.

At the pivotal end of the type bars 22 are teeth 25 which mesh with the teeth on the depression of the latter swings the type bar 22 into printing position as shown in the dotted lines. An escapement universal bar 26 extends across the machinebetween arms 27 and 28. Said arms are pivotally mounted at 29 and carry a bracket 30, on which latter are mounted a fixed escapement dog 31 and a loose dog 32, said last mentioned dog being pivotally mounted-0n an upper portion 33 of the bracket at 34 so that it can swing transversely of the base of the machine.

Another universal bar 35 serves to operate the ribbon vibrating mechanism and the ribbon feed, a ribbon feed pawl 35a and wheel 35?) being shown in Fig. 1 and the ribbon vibrating mechanism designated generally at 350, being likewise shown. The ribbon feed and reverse mechanism are more fully described in my copending application Serial No. 245,790, filed January 10, 1928,

while the ribbon vibrator mechanism per se is also more fully described in a copending application Serial. No. 245,791, filed January 10, 1928, and I will not, therefore, further describe the details of these two mecha-- nisms.

One of the particular features of my invention, so far as concerns the escapement and back spacing mechanism, is the provision of a unitary member which embodies all of the vital operating parts of the escapement mechanism as well as of the back spacing device. This unit comprises a base portion 36from'which a web member 37 extends vertically upwards, where it is developed into two arms 38 and 39 which spread from a central channel portion 40. At the ends or sides of the arms 38 and 39 are formed journaled portions for a variety of uses. The arm 39 has two portions formed integrally therewith in which members are pivotally mounted; while the other arm 38 is bored to provide another journal.

The journal in arm 38 and the lowermost journal portion in arm 39 are designated as 41 and 42 and are in alignment to provide a journal for a shaft 43 which is connected to the ribbon changing mechanism for the ribbon vibrating device,-

just describe also acts as a support for the universal bars 26 and 35, which latter are arranged in nested relation, as best shown 111 Fig. 2, and extend straight across the machine, thereby afiording a very advantageous leverage between the key levers and the operating parts of the escapement and ribbon vibrator because the said universal bars are- 7 engaged progressively closer to the center on a which the intermediate links are mounted as the side keys are approached, whereby,-at that point where the pressure is normally lessened, namely,the point where the little finger engages the keys, the leverage 188116 11 that the power obtained is greatest. This is a feature of marked advantage and is more fully described and claimed in my copending applications, Serial No. 720,255, filed June 16, 1924, and Serial No. 237,392, filed December 3, 1927.

- The aforesaid universal bars are provided a; ith arms 2728 (hereiofmlndictled) and portions -51 extending rearwardly therefrom, whereby each of said bars comprises a U-shaped entity which is pivotally mounted for vertical movement at the .sides of the We on journals about the shaft "43. As best shown 'in Fig. 2, the aforesaid rearwardly extending arms are bowed inwardly at the points of pivotal suspension to afford a more compact disposition of the same. The arms are continued to the rear where they termi- Hate in stop portions 50a and 51a, which contact against arms bent from a bracket 53 secured to the web 37 of the unit mounting. By adjusting the distance between the said portions,I, am enabled to accurately predetermine the limits of the up and down travel of the universal bars.

Said universal bar 26 is utilized to provide the escapement for the typewriter machine and to this end a bracket member 54 is sus pended between the arms 50 and 51, the same eing disposed below the shaft 43 and being formed preferably rigidly and integrally with said arms 50- -51, thereby obtaining marked manufacturing benefits in the way of simplicity of design and economy of production.

Mounted on said bracket member 54 is the aforedescribed support 30 which carries the heretofore mentioned limber pawl or loose dog 32 and the fixed dog 31. These dogs coo crate with a wheel 55 provided with slig tly beveled teeth which, as shown, are so chamfered as to eliminate the wear caused by the dog as it leaves the wheel. Said wheel 7 otally mounted pawl 58. The latter is carried 3 between a toothed wheel 59 and a circular face plate 60, and is urged toward the eriphery of the wheel 57 bya spring 61. The atter spring is mounted between the wheel 59 and the plate 60 on a pin 62, and the pawl 58 is mounted therebetween'on a pin 63.

A feed pinion 64 is secured to the plate 66 and the whole is rotatably mounted on the shaft extension of the shaft 56 by a lock nut 67, the said members 59, 60 and 64 operating as a unitf-it being noted that thepinhn 64 is secured to the plate 60 by pins 6 68.

A rack 69 intermeshes with thefeed pinion 64 and is, of course, carried b a carriage shift frame-70', the latter supporting a platen 71 and a paper table-72 cooperating therewith. The pafper table 72 has a scale 7-3 fas tended to the orward portion thereof to bear againstthe platen as required. The carriage 70 comprises'an upper rail 74 and a lower rail 75 having my improved bearing members 7 6 therebetween- The manner in which said hearing members 76 are. associated with the carriage parts is described more in detail in my copending application Serial No. 191,656 filed May 16, 1927.

A releasing member 77 is pivotally mounted at 78 on the carriage frame and carries the toothed rack 69 at its lower end so that the latter may be moved outwardly from the back of the machine to release the said rack from engagement with the escapement wheel. In the machine shown in Fig. 4 l have assumed that'the carriage rack 69 is continually urged in the direction of the arrow as by a spring or other power means, whereby as the escapement wheel is actuated by the movement of the universal bar when struckby the ally moved so that said dogs are raised and lowered.

Reference to Figs. 2, 3and 5 will best disclose the manner in which this vertical movement of the dogs results in a space-by-space escapement of the mechanism. The initial upward movement of the rear end. of the bracket brings the fixed dog 31 into en agement with the teeth of said wheel 55 an lifts the limber pawl 32 out of engagement therewith. A spring 79 then draws the pawl 32 to the left (see Fig. 3) as far as is permitted by a stop 80 which is formed on the upstanding portion of the bracket. The tooth 32 is therebymoved pivotally about its connection point 34 and after abutting against the stop '80 stands above the next inter-dental space with which it is to engage.

The upward movement of the key lever now permits the foot 17 to rise, whereupon the universal bar 26 returns and lowers the rear end of the bracket together with the dogs positioned thereupon. Such action brings the limber pawl 32 into engagement with the inter-dental space directly thereunder and t the same time removes the holding pawl 3' from its engagementwith the teeth on the lower side of the pawl. The power imparted to the rack 69 then moves the wheel 64 and, through the clutch connection of the pawl 58 and wheel 57,-transmits said motion to the said pawl and turns the latter as far a'sisapermitted bv the movement'of the limber pawl 32. The latter finally abuts against the inner end of a stop screw 81 thereby stopping the escapement and fixing the carriage in position for the next printing stroke. The stop screw 81 can be adjusted to vary the amount of movement of therack 69 upon each escapement movement of the dogs.

When, however, it is desired to return the carriage to theleft-hand margin printing point, that is in a direction opposite to the arrow of Fig. 4, it is not necessary to provide means for disengaging the dogs from the said wheel 55. This operation is taken care of in the clutch action between the Wheel 57 and the pawl 58, it being noted that when the rack is moved to the left (Fig. 4) .the aforesaid awl 58 slides over the top of the teeth of 57 and does not cause the shaft 56 to turn.

This particular clutch-like connection between the said wheel and the escapement part of the escapement mechanism but is also so much a part of the back spacing mechanism that I will now show that the two mechanisms are not separable but may properly be described and claimed in this single application.

As I have heretofore indicated, In improved back spacing mechanism is 0 particular advantage because the operation is directly on the feed pinion, and moreover,

' because the elements thereof are so arranged that substantially little or no back lash is necessary in the operation of the aforesaid back spacera feature which those skilled in the art will appreciate. Moreover, as I have heretofore indicated, the number of parts required to effect this desirable operation are reduced to a minimum by the particular and novelmanner in which I associate the back spacing elements with the escapement parts of the machine.

Referring now particularly to Figs. 2 and 4, I have already spoken of the heel 59. which is somewhat of a star-wheel in structure and which is secured to, and moves with. the feed pinion 64. In order to move said wheel 59 space-by-space in a counterclockwise direction, I provide a back spacing member 82 having an actuating tooth 83 and a stop or holding tooth 84.2 These teeth are preferably,in the embodiment of my invention here shown,formed integrally on the member 82, which latter is pivotally mounted at 85 on an upstanding arm 86 of a main backspacing member 87. The member 87 is pivotally mounted at 88 on a lug 89 which is secured to a channel 90 of the typewriter frame. Said member 87 has its right-hand end (viewed as in Fig. 4) urged upwardly and its left-hand end urged downwardly by. a spring 91 which is connected also to the spring 97 connects a lug portion 98 of the member 82 with a parallel extending portion 99 of the arm 86 of the lever 87, movement of the member 82 under the influence of said spring being limited by engagement between a laterally bent lug portion 100 of said member and the upper edge of the portion 99.

When said back space key 94 is depressed,

the rear end 95 of the lever 92 is raised,

whereupon the left-hand end of back space lever 87 is raised into the position shown in the dotted line (see Fig. 4). This movement causes the portion of lever 87 to the right of pivot 88 to move downwardly. This movement brings the tooth 83 into engagement with the upper side of one of the teeth of the wheel 59 and causes said wheel tomove in nism is so adjusted that this tooth thus stops the movement of said wheel tooth at suchtime as to provide a substantial one space movement of said wheel. The surfaces of the wheel and of the stopping and actuating teeth, as well as the provision of spring 97 to accommodate clockwise movement of the member 82 about its pivot 85, are such that the release of the back space key then permits the member 82 to swing out from engagement j with said teeth and back into proper position without the necessity of moving the wheel 59 in a clockwise direction, which latter movement would occasion back lash.

Upon release of the back-space key 94 the lever 87 is returned b the spring 91 to the "full-line position of *ig. 4, the member 82 turning slightly in a clockwise directionabout its pivot 85 as the tooth 83 rides over the tooth of the wheel 59 directly above it. As soon as these teeth disengage the spring 97 returns the member 82 around pivot 85 to its normal operative position determined by the engagement of the horizontally extending lug 100 with the upper edge of the .portion 99. Again the upward movement of the right-hand portion of the lever 87 is positively stopped by engagement of the upper edge of said portion with a stop port'zon 101 of a fixed part 102 on the unit frame heretofore described. I

It will be noted that the counterclockwise movement of the wheel 59, although it moves the rack 69, and therefore, the carriage spaceby-space to the left, does not in any way affect the escapement of said wheel or dogs whereby a most advantageous operation is produced.

As heretofore indicated, the utilization of a unit frame member upon which both universal bars may be mounted is of distinct advantage. not only in markedly reducing the cost of manufacturing a machine of this character, but also in providing very few parts which may need replacementor which may be lost. The ease of assembly is surprising, and all of these advantages may be largely attributed to the integral unitary base member which permits the assembly of all the escape ment portions and of the nested universal bars before the insertion of the same into the machine frame.

Although I have in my copending application, Serial No. 37,085, filed June 15, 1925, described in detail the ribbon vibrator mechanism utilized'in my machine, I will briefly refer to the same in order to round out the.

description of the present showing, particularly as relating to the mounting of both universal bars on the aforesaid-bracket. As.

103 and 104, which are journalled about the shaft 43 as shown. I

Particular attention is directed to the manner in which the journal portions of the arms mounted on shaft 43 are formed. As shown in section the arms are expanded at 103 and 104' to form abearing and also a separator from the next journalled arm. This is a feature of distinct advantage and economy.

' The rear portions 103a and 104a, of said arms, as well as the rear portions 50a and 51a, move between stop members of the character heretofore described; it being understood, of course, that said stop members,both upper and 'lower,-may be adjusted to change the limits of movement of the universal bars.

' A bracket member 105 extends between said arms and serves to connect the elements of the ribbon vibrator mechanism, which is indicated generally at 350, with the universal bar 35 so that movement of the latter actuates the said ribbon vibrator irrespective of whether the platen 71 is in upper or lower case position and irrespective of whether a red, black or stencil impression is requiredas described in the last indicated copending application.

The stop portions for the rearwardly extendmg ends of the universal bars are formed integrally on brackets secured to either side of the escapement unit. For purposes of illustration, I have shown these stop portions with as much of the universal bar structure as is necessary in greatly enlarged dimensions (see Figs. 2a and 2b). I have, moreover, for simplicity illustrated only the bracket at one side of the machine, in this case the one which is at the top of Fig. 2, or the one which cooperates with the rearwardly extending portions of arms 51 and 103.

The aforesaid stop members are formed or bent from a stamping which is provided with an arm 106. Said arm is secured to the escapement .unit by screws at 107, and said stamping is further bent into shape to comprise bars or stop members. The pair of tute upper and lower limiting stops for the rear end 1030 of the arm 108.

stop members.

A lever member 109 is mounted on pin 110, it being noted that the mounting is effected through a slot connection so that the left-hand end of said lever 109 may move vertically over said pin. The other end 111 of said lever is held between a head 112 and a collar 113 of a screw member 114, the latter being seated in the portion 36, as best shown in Fig. 2a. The aforesaid lever 109 pivots about a portion 115 of the stamping, being held in cooperative pivotal position in a notch 116 therein.

A spring 51d extends between the end 51a of the side arm 51 and a lug 51c bent out from the lever 109. This spring 51d tends to return the arm 51a to its lowermost position. In like manner a spring 103d is connected between the pin 110 and the rear end 103a.

The lever structure just described is utilized to vary the tension of spring 51d. This is an, important adjustment, but one which is frequently neglected because of the difiiculty of arranging the same in connection with the In my structure, however, thescrew 114 may be easily moved in an upward or downward direction which results in carrying the end 111 of the lever 109 along therewith. This moves the said lever 109 about the pivotal notch 116 (the slot connection with the pin 110 permitting such movement) and results in varying the tension on the spring 51d.

Another feature which is of importance in connection with this particular type of universal bar stop is the resiliency or snappy kick-back of the bar,and therefore, of the type hair -resulting from the stop being made against a more or less resilient piece of material. Such resiliency is obtained because of the stops being bent out from a piece of said material. of particular importance in connection with the universal escapement bars because such resilient snappy movement contributes markedly to the speed with which the escapement operates.

I have described but one embodiment of my invention as it relates to what -I believe is an inseparable disclosure of back spacing mechanism and escapement device because of the part which the carriage-like connection plays in both phases of the invention. It is of course true that many of those skilled in the art may utilize the features of my invention in many different forms without departing from the spirit of the present invention and I desire, therefore, that this invention be broadly interpreted and not be limited to the present specific details employed in the present description but rather that it be limited 1 only by the scope of the appended claims and printing-stro e-operated escapement uni- This kick-back feature is' versal bar member, a dog carrier carried by said member, an escapement wheel disposed in a vertical plane, fixed and loose dogs mounted vertically one above the other on said carrier and on opposite sides of said es-- capement wheel for vertical movement with said carrier to escape said escapement wheel, a feed wheel and a rack engaged therewith, andclutch means between said escapement wheel and said feed wheel permitting the reverse movement of said feed wheel while said escapement wheel remains stationary, the axis of said escapement Wheel being substantially perpendicular to the pivotal axis of said dog carrier.

2. In a typewriter, a pivotally mounted, printing-strokeoperated escapement universal bar member, a dog carrier carried by said member, an escapement wheel disposed in a vertical plane, fixed and loose dogs mounted vertically one above the other on said carrier and on opposite sides of said escapement wheel for vertical movement with said carrier to escape said escapement wheel, the fixed dog being fastened to said carrier and partaking of all the vertical movements thereof and the loose dog being horizontally movable to effect escapement, a feed wheel and a rack engaged therewith, and clutch means between said escapement wheel and said feed wheel permitting the reverse movement of said feed wheel while said fixed dog remains in engagement, the axis of said escapement wheel being substantially perpendicular to the pivotal axis of said dog carrier.

3. In a typewriter, a pivotally mounted, printing-stroke-operated escapement universal bar member, a dog carrier carried by said member, an escapement wheel disposed in a vertical plane, fixed and loose dogs mounted vertically one above the other on said carrier and on opposite sides of said escapement wheel for vertical movement with said carrier to escape said escapement wheel, a feed wheel and a rack engaged therewith, and clutch means between said escapement wheel and said feed wheel permitting the re-- verse-movement of said feed wheel while said escapement wheel remains stationary, said;

said gear upon back space movement of said rack, the axis of said escapement wheel being substantially perpendicular to the pivotal axis of said dog carrier.

4. In a typewriter, a pivotally mounted, printing-stroke-operated escapement universal bar member, a dog carrier carried by said member, an escapement wheel disposed in a vertical plane, fixed and loose dogs mounted vertically one above the other on said carrier and on opposite sides of said escapement 7 wheel for vertical movement with said carrier to escape said escapement wheel, a feed wheel and a rack engaged therewith, and clutch means between said escapement wheel and said feed wheel permitting the reverse movement of said feedwheel while said escapement wheel remains stationary, said clutch means comprising an actuating pawl on said feed wheel, a uni-directional gear fastened to the shaft of said escapement wheel, and means holding said pawl in contact with said gear, said gear being engaged and moved by said pawl when said rack moves upon release by said dog system but said pawl sliding over said gear upon back space movement of said rack, the axis of said escapement wheel being substantially perpendicular to the pivotal axis of said dog carrier.

5. In a typewriter, a pivotally mounted bracket, a printing-stroke-operated escapement universal bar rigidly secured to'said bracket to move the latter vertically, an escapement wheel disposed in a'vertical plane, a fixed dog on said bracket below said escape ment wheel, a loose dog disposed vertically above said fixed dog and above said escapement wheel and secured to said bracket to move horizontally with respect thereto, whereby said escapement wheel is escaped upon vertical movement ofsaid bracket, a feed wheel and a rack in engagement therewith, means for moving said rack when said dogs escape said escapement wheel, and pawl and gear clutch means between said feed and escapement heels, the axis of said.escape ment wheel b ing substantially perpendicw lar to the pivotal axis of said bracket.

6. In a typewriter, a pivotally .mounted bracket, a printing-stroke-operatedescape-' ment universal barrigidly secured to said bracket to move theglatter vertically, an esbracket.

capement wheel dis os ed in a vertical lane, a fixed dog on sai bracket below said es-' 'capement wheel, a loose dog disposed vertically above said fixed dog and above said escapement wheel and secured to said bracket to move pivotally about a substantiall vertical axis with respect thereto, where y .said escapement wheel is escaped upon vertical pinion and said escapement wheel housed be-. tween said feed pinion and said back spacing wheel and partly carried by said securing means.

8. In a typewriter, an escapement and back spacing mechanism comprisin an escapement wheel, a feed pinion, a' ack spacing wheel, rivets securing said back spacing wheel in rigid relation to said feed pinion, and a ratchet and pawl-mechanism connecting said feed pinion and said escapement wheel and housed between said feed pinion and said back spacing wheel, the pawl of said mechanism being ivotally mounted on one of said rivets and eing provided with a retaining spring supported by another of said rivets.

9. In a typewriter, an escapement and back spacing mechanism comprising an escapement wheel, a feed pinion, a ck spacing wheel, rivets securing said back spacing wheel in rigid relation to said feed pinion, and a ratchet and awl mechanism connecting said feed pinion and said escapement wheel and housed between said feed pinion and said back spacing wheel, the pawl of said mechanism being pivotally mounted on one of said-rivets.

In witness whereof, I have hereunto subscribed my name.

' MAX GARBELL.

movement of said bracket, a feed wheel and a rack in engagement therewith, means for moving said rack when said dogs escape said escapement wheel, pawl and gear clutch means between said feed and escapement wheels, and adjustable means for predetermining the extent of movement of said 7. In a typewriter, an escapement and back spacing mechanism comprising an escapement wheel, a feed pinion, a ck spacing wheel, means securing said back spacm wheel in rigid relation to said feed p1n1on, an a one- .way driving connection between said feed CERTIFICATE or CORRECTION.

Patent No. 1,841,108. Granted January 12, 1932, to

MAX GARBELL.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 1, line 26, strike out the word "reduction"; page 2, line 111, after "carriage" insert the words shift frame; and that the said Letters Patent should be read with these correction therein that the samemay conform to the record of the case in the Patent Office.

Signed and sealed this 22nd day of March, A. D. 1932.

M. J. Moore, (Seal) Acting Commissioner of Patents. 

